Apparatus for welding film



April 18, 1939. C. SCOTT APPARATUS FOR wswum FILM Filed April 15, 1935 2 Sheets-Sheet l minus:

FILM SHEET Zlwvemtoc Cl de J'mw April 18, 1939. c. scoTT 2,154,474

APPARATUS FOR WELDING FILM Filed April 15, 1953 2 Sheets-Sheet 2 ADJUSTMEN I OF PRESSURE FAPER QUTTER wuemtoz Clyde Jcol'Z' w ia i w 5 Z Patented Apr. 18, 1939 UNITED STATES PATENT OFFICE The following described invention relates in general to a film welding process and the machines by which it is applied. Films of reconstructed cellulose, or other soluble cellulose compositions can be produced successfully in strips or webs of any desired length. Such webs of cellulose may in their final form include a coating which while normally stable and non-tacky, may be rendered adhesive by appropriate manipulation.

It is an object of my invention to provide a process and apparatus by which such a film of coated material either continuous or in separate sheets may be applied in a continuous manner to sheet or web material such as paper, fabric or the like. It is also within the scope of my invention to apply such films mechanically upon opposite sides of a web of paper or the like.

Among the objects of my invention is the provision of means for applying the requisite heat and pressure necessary to successfully weld the film to a web of supporting material such as paper, fabric or the like. By the term we1ding" it is to be understood that there is involved the establishment of a tenacious condition of one coated surface of the film and that this coating shall thus be rendered adherent to other material by pressure. The film coating is rendered adhesive by heat and cohesive by pressure accompanied by heat. The film is thereby attached to the adJacent web so closely as to merit description as a weld.

In the feeding of sheets of paper and a web 01' coating film together through the welding machine there is likelihood that failure of the two materials to register accurately will bring a portion of the film with its dry adhesive coating into contact with the heated roller.

This would cause the film to stick to the roller and for this reason one of the objects 01' my invention is to protect the roller by a guard or slip strip of paper or the like which can be separated from the welded sheets and film.

A further object of my invention is to moisten or otherwise treat the paper or fabric prior to welding, or to compensate subsequently for the disturbance of normal conditions of the material caused by the welding operation so that the welded product shall have the desired flexibility and flatness.

It is also an object of my invention to provide for applying a coating of film on opposite sides of a single web 01' paper or fabric either simultaneously or by successive operations.

The composite film and web product resulting from this process and machine has diverse uses among which may be briefly listed the production 01' water-proof, moisture-proof and odor repellent wrappers .ior goods and materials; the ornamentation and water-proofing of printed or otherwise decorated papers including posters and similar reinforced or embellished sheets.

By means oi this process and apparatus I am enabled to produce a developing or printing paper sensitized for use in the direct production 01' X-ray and other photographs. It is also possible thus to apply a film oi photosensitive gelatin to a web oi supporting paper so that the two may be handled together during exposure and dis veiopment and then separated for subsequent mounting if desired.

The novel arrangement of structural details whereby the above objects are attained forms a further feature oi this invention. Other objects of my invention and advantages of the improved process and apparatus will be evident from a description of the following preferred examples of the process in which Fig. 1 is a diagrammatic view of the essential mechanism for welding the co-terminous sheets oi. dim and paper in registration;

Fig. 2 is a further illustration oi welding continuous webs;

Fig. 3 is a view oi the process as applied to uniting sheets of paper to a continuous film and protecting portions or the latter;

Fig. 4 is a similar view where continuous films are united to opposite sides of separate sheets and Fig. 5 is a similar view where the paper to be covered is in the form of a continuous web.

By way of example, I have shown a frame or standard I in which a lower roll 1 is Journalled at 8. This roll is 0! highly polished steel and is hollow to receive steam or other heating fluid.

The heating fluid is admitted through the hollow Journal 0 in the bearing 8.

A second roller 8 cl suitable hard substance such as hard rubber or paper is carried on a shaft Ill mounted in a vertically sliding journal hearing II. This bearing H is movable vertically in a slot 12 of the standard 6 and adjustment is accomplished by means of the arflusting screw Ill and nut ll. It is to be understood that a stand ard I and its associated bearings is provided on each opposite side of the machine.

This pair oi rollers forms the essential features of equipment for carrying out the procws in its broader aspect. By feeding through this pair of rollers, a sheet 01 illm II and a coterminous sheet oi paper. fabric or metal It with their edges in registration the sheets are firmly united by the momentary pressure and heat from the rollers. It is to be remarked that the surface of the film facing the sheet of paper has a thin skin or coating of some suitable natural or artificial resin which becomes adhesive when heated. By using a solid rather than a fluid or viscous adhesive it is possible to avoid all side slip of the sheets when passing through the rollers.

Where the film and paper, fabric or foil are in the form of continuous webs, then they may be individually fed from rolls. Such an arrangement is shown in Fig. 2.

Suitably mounted on a stand not illustrated, there is provided a series of idle rollers i1 and il. The roller II has a web it of this specially manuiactured cellulose material. This cellulose film is of any desired length and one or both sides have coatings of normally solid adhesive material. Such material may be a natural or artificial resin of the thermo-adhesive type or a synthetic polymerized vinyl acetate or the like.

The roller it carries a continuous web ll of paper which it is intended to weld with the him is.

' Under those circumstances where the paper is in sheet form and the film a continuous web, the adhesive side of the latter may not all he engaged by the paper but may come in contact with and attach itself to the heated roll I. To prevent this action the process is carried out as shown in Fig. 3. The standard I carries Journailed thereon the lower heated roll I and the upper adjustable hard roll I. In addition to the continuous web of film II fed from roll ii there is provided a supply of sheets of paper II.

From a suitable position and from a reel 22 a second guard or slip strip 23 of paper is fed over an extended angular distance of the heated roll I and beneath the sheets of paper Ii. In this way any portions of the adhesive surface of film it not attached to the paper 2! will stick to paper web 23.

Issuing from the pair of rolls will be the welded paper film II which may be conveniently rolled up on roll 25 with the coated or film side out. In this way the coated paper when unrolled will lie fiat.

The web 23 is pulled away from paper 2i and caused to travel down table 28. At the end of table 28 the web II over a cutter bar and is sheared by cutter ll so that the successive sections form the pile I8.

The extent of preliminary travel of the webs i8 and 23 around the roller I and 8 prior to their union is used to impart heat to the webs so that the welding or union is assisted. The heat from the roller 1 is imparted by indirect transfer through roller 8. This preliminary heating may be adapted to the process regardless of whether the webs being heated are of paper or of film.

The extent of the heating is in some degree dependent upon the thickness and type of the webs passing through the rollers.

The process just described is equally well adapted for welding or. uniting two strips of film with an intermediate layer of paper. Where this intermediate layer is in separate sheets the procedure is that outlined in Fig. 4. Here the same pair of heated rollers receives the web I! of film and a second roll web of film 29 drawn from a supply ill. The web of film 20 takes the place of the paper web 13 and obviously has its adhesive coated face uppermost. The separate sheets 21 of paper, fabric or the like are fed between the films II and 2|. In this instance the adjacent edges of the sheets Il may not be in contact and the result is that the films l9 and 28 are thus sealed together beyond the edges of the sheets It. The delivery of the coated sheets 2| may be in a continuous strip or the sections separated in the manner already described with respect to the form shown in Fig. 3; i. e., the laminated material may be sheared by cutter 21 so that the successive sections form the pile II.

In Fig. 5 there has been illustrated a procedure for coating both sides of the web of paper 2i by two layers of film in succession. The standard I and the associated rollers I and 9 are arranged and operate as has been described already.

The feed of the film l9 and paper 2| to be coated, has been arranged so that the film is above the paper and on the side of the solid roller I. In this way the heat from the roller I is applied to the web of paper and the latter primariiy heated before the film is applied. In this way the heat passes through the paper to the near side of the film and does not affect the latter materially except to provide for rendering the lower coated surface of the film adhesive for welding (see Fig. 2).

A second stand Ii is provided beyond the standard 5. 0n the stand II there is provided a lower roller 32 of hard rubber or paper similar to roller 9. This roller 32 is mounted on fixed bearings 33.

The upper roller 34 is hollow and similar to roller 1. Roller 34 is provided with a vertically movable Journal bearing 35 and the hollow shaft 88 is also equipped to introduce the heating fluid. Vertical guides 31 permit the movement of the journal 16 under the adjustment of the screwthread 38 and adjusting nut 39.

In advance of the roller 32 is provided a second roller supply 40 from which the film 29 is drawn upwardly to the stand it. This film 25 is coated on its upper surface with a resinous or similar substance which will be thermoplastic and adherent.

The paper web 2|) drawn through the standard 5 has applied to its upper side a coating of film ll due to the momentary application of pressure and heat. As the coated paper 20 travels between the rollers 32 and 34 it is coated on its lower exposed paper side with the cellulose film 29. Thus the strip ll leaving the rolls 32 and 34 is a three-ply article having a paper layer 20 coated on each side with a film.

It will be observed that in the rollers l and 9 the heat is transmitted through the paper to the film so that the paper is heated to a greater degree than is the film. when the second film 2! is applied the heat has been shown as applied through the partially coated paper. It may, however, be applied directly to film 29 by making the roller 3!, the heated one.

The heating of the sheets and webs is controlled depending on their thickness. In like manner, where the heating is found to stiffen or dry the material, the coated web may be humidifled or otherwise treated before removal for storage or use.

The operations above described permit the ready and uniform production in a continuous manner of a paper or fabric strip which is coated on one or both sides with a water-proof film. This film supplies a transparent or decorative coating on one or both sides of the paper which enhances the decoration or printing upon the ll per andgivesthepsperquslifles ofrepelling water. odors or the like.

The adhesion or-welding between the paper and oneor'bothfilms maybevariedbycbange inthecharacteroftberesinouscoatingsofthe iilmandthedegreeoftensionprovidedforthe rollers. In this way the film may be supported and reinforced by the paper until such time as it is desired to separate the film for independent use. 'I'hisisdesirablein someformsofphotograp lns. photolithography or the production of transparencies.

While the preferred form. of my invention has been described it is to be understood that the scope thereof is limited only by the scope of the following claims.

What I claim is:

1. A welding machine for uniting pre-formed plastic film to a base material, comprising in combination a roller carrying a web of preformed plastic him, a roller carrying a web of base material, uniting means comprising a metal roll having a polished surface adapted to provide a rigid pressure and a non-metallic roll adapted to provide a counter pressure, means for heating said metal roll, means for maintaining said metal roll in position to heat said non-metallic roll by indirect transfer, means for adjusting the interfacial pressure between said metal roll and said non-metallic roll whereby the feeding of the film and base material to be united is through said rolls.

2. A welding machine for uniting pre-formed plastic him to a base material. comprising in combination a roller carrying a web of Dre-formed plastic illm, a roller carrying a web of base material, uniting means comprising a metal roll having a smooth surface adapted to provide a rigid pressure and a hard paper roll adapted to provide a counter pressure, means for heating said metal roll, means for maintaining said metal roll in position to heat said paper roll by indirect transfer, means for adjusting the interfacial pressure between said metal roll and said paper roll whereby the feeding of the film and base material to be united is through said rolls.

3. A welding machine for uniting pre-formed plastic film to separate sheets of base material, comprising in combination uniting means comprising a metal roll having a smooth surface adapted to provide a rigid pressure and a hard roll comprising a rubber surface adapted to provide a counter pressure, means for heating said metal roll, means for maintaining said metal roll in position to heat said second named roll by indirect transfer, means for adjusting the interfacial pressure between said metal roll and said second named roll.

4. A welding machine for uniting pre-formed plastic film. to a base material, comprising in combination uniting means comprising a metal roll having a smooth surface adapted to provide a rigid pressure and a non-metallic roll adapted to provide a counter pressure, means for supplying heat to said metal roll, means for maintaining said metal roll in position to heat said non-metallic roll by indirect transfer, means for adjusting the interfacial pressure between said metal roll and said non-metallic roll, means comprising a roller carrying a web of pre-formed plastic film, said roller being positioned to feed plastic film into direct contact with said non-metallic roll, means comprising a roller carrying a web of base material, said roller being positioned to feed said braalsie material into direct contact with said metal 6: A welding machine for uniting pre-formed plastic iilm to two sides of a base material, comprising in combination means comprising a roller carrying a web of pre-formed plastic film and a second roller carrying a web of pre-i'ormed plastic film, uniting means comprising a metal roll having a smooth surface adapted to provide a rigid pressure and a non-metallic roll adapted to provide a counter pressure. means for supplying heat to said metal roll, means for maintaining said metal roll in position to heat said nonmetallic roll by indirect transfer, means for adlusting the interfacial pressure between said metal roll and said non-metallic roll whereby the feeding of the two films and base material to be united is through said rolls.

6. A welding machine for uniting pro-formed plastic him to two sides of a base material, comprising in combination uniting means comprising a metal roll having a smooth surface adapted to provide a rigid pressure and a non-metallic roll adapted to provide a counter pressure, means for supplying heat to said metal roll, means for maintaining said metal roll in position to heat said non-metallic roll by indirect transfer, means for adjusting the interracial pressure between said metal roll and said non-metallic roll, means comprising a roller carrying a web of pre-formed plastic film and a roller carrying a web of base material, said roller carrying said film being positioned to feed said film into direct contact with said non-metallic roll, said roller carrying said base material being positioned to feed said material into direct contact with said plastic film and said metal roll, a second metal roll having a smooth surface adapted to provide a rigid pressure and a second non-metallic roll adapted to provide a counter pressure, means for supplying heat to said second named metal roll, means for maintaining said second named metal roll in position to heat said second named non-metallic roll by indirect transfer, means for adjusting the interfacial pressure between said second named metal roll and said second named non-metallic roll, means comprising a third roller carrying a second web of pro-formed plastic film, said roller carrying said film being positioned in advance oi said second named metal and non-metallic rolls and being positioned to feed said film into direct contact with said base material.

'7. In an apparatus for uniting pre-formed plastic film to a base material. means comprising a metal roll having a smooth surface adapted to provide rigid pressure and a non-metallic roll adapted to provide a. counter pressure, means for supplying heat to said metal roll, means for maintaining said metal roll in position to heat said non-metallic roll by indirect transfer, means for adjusting the lnterfacial pressure between said metal roll and said non-metalllc roll and means comprising a roller carrying a web of slip sheet material.

8. In an apparatus for uniting pro-formed plastic film to a base material, means comprising a smooth metal surface adapted to provide rigid pressure, means for providing a resilient counter pressure, means for preventing adhesion between plastic film and pressure means, said means comprising slip sheet fibrous material.

9. In an apparatus for uniting pre-formed plastic film to a base material, means comprising a metal roll having a smooth surface adapted to provide a rigid pressure and a non-metallic roll adapted to provide a resilient counter pressure, means for preventing adhesion between plastic dim and pressure means. said means comprising slip sheet fibrous material, means for cutting and removing sections oi slip sheet material. said means comprisim a cutter bar.

iii. In an apparatus for uniting pre-iormed plastic iilm to a base material. means comprising a metal roll having a smooth surface adapted to provide a rigid pressure and a non-metallic roll adapted to provide a counter pressure, means for heating said metal roll, means for maintaining said metal roll in position to heat said non-metallic roll by indirect transfer, means tor adjusting the interiaciai pressure between said metal roll and said non-metallic roll. means for cutting and removing sections of laminated material, said means comprising a cutter bar.

11. In an apparatus for uniting pre-tormed plastic him to a base material. means comprising a metal roll having a smooth surface adapted to provide a rigid pressure and a non-metallic roll adapted to provide a counter pressure, means for heating said metal roll. means for maintaining said metal roll in position to heat said non-metallic roll by indirect transfer, means for adjusting the interracial pressure between said metal roll and said non-metallic roll. means comprising a roller carrying a web of pre-formed plastic film andarollercarryinga webolslipsheetiibms material. means for preventing adhesion between plastic film and pressure means.said means comprising slip sheet fibrous material. means (or cutting and removing sections of slip sheet material, said means comprising a cutter bar, and means for winding united material comprising plastic iiimintoarollwiththefllmsideout.

12. In an apparatus for uniting pre-tormed plastic film adapted for welding to a base material, means a metal roll having a smooth surface adapted to provide a rigid pressure,meanscomprisingarubberrolladaptedm provide a counter pressure, means for heating said metal roll, menu for maintaining said metal roilinpositiontoheatsaidrubberroiilvyindirect transfer, means for adiusting the interracial pressurebetweensaidmetalrollandsaidrubber roll, means for preventins adhesion between piasticiilmandsaidpressuremeans,saidmeans comprising iibrous slip sheet material, said metal rollandsaidrubberrollcomprisingthemeans and being in position for applying the heat and pressuretorcausingtheiaminationottbeplasflc him to the base material.

CLYDE 8001.1. 

